Electric conducting-wire.



No. 702,725. Patented lune I7, I902.

H. &. E. HAMMESFAHR. Y

ELECTRIC CONDUCTING WIRE.

(Application filed Feb 28, 1902.)

(No Model.)

//v VENTOHS BY I ATTORNEYS.

WITNESSES:

UNITED STATES PATENT OFFICE.

HERMANN HAMMESFAl-IR AND ERNEST HAMMESFAHR, OF NEYV YORK, N. Y

ELECTRIC CONDUCTING-WIRE.

SPECIFICATION forming part of Letters Patent No. 702,725, dated June 17,1902- Application filed February 28, 1902. Serial No. 96,166. (Nomodel.)

T0 all whom it may concern:

Be it known that we, HERMANN HAMMEs- FAHR and ERNEST HAMMESFAHR,citizens of the United States, residing in New York, borough ofBrooklyn, and State of New York, have invented certain new and usefulimprovements in Electric Conducting-Wires, of which the following is aspecification.

This invention relates to certain improve ments in electric wires ofthat class which are insulated in such a manner that an effectiveprotection against fire is obtained, so that the Wires can be appliedwithout requiring any additional safeguards against fire. For thispurpose the invention consists of an electric insulated wire providedwith a covering layer formed of strands of filaments of spun glassbraided on the same, as will be fully described hereinafter and finallypointed out in the claims.

In the accompanying drawings, Figure 1 represents a side elevation of apiece of .our improved insulated electric wire covered with one layer ofbraided spun glass. Fig. 2 is a side elevation of another wire coveredwith two layers of spun glass and an intermediate layer of braidedcotton or other threads; and Figs. 3 and l are respectively verticaltransverse sections on line 8 3, Fig. 1, and 4 4, Fig. 2, drawn on alarger scale.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, a represents an electric conducting-wire, andb a braidedlayer of spun g1assthat is to say, a layer the strands ofwhich are formed of a number of filaments of spun glass that are braidedon the wire a by a braiding-machine in the same manner as other braidedlayers. In most cases one braided layer of spun glass is sufficient toprotect the wire and prevent danger of fire. In some cases, however,several layers 1) b of spun glass may be used interiorly and exteriorly,as shown in Fig. 2, in which case the interior and exterior layers areseparated by an intermediate layer of braided cotton threads 0, as shownin Fig. 2.

It is preferable to give the covering layer of spun glass a coat ofsuitable varnish, so as to protect the thin filaments of spun glass,especially when laying the wires.

The covering-braids of spun glass form a reliable insulation for thewire and prevent any danger of fire, they being even a protection to thewire, as even in the case of fire the covering of the wire cannot beburned even when exposed to the heat of the fire, as the glass coveringforms a vitrified glaze around the wire. The electric wires insulatedbya spun and braided glass covering form a suitable protection againstdanger of fire by ignition due to the electric current and can be usedwithout requiring any further additional protecting media.

Having thus described our invention, we claim as new and desire tosecure by Letters Patent 1. An insulated electric conductor, consistingof a wire, and a covering layer formed of strands of filamentsconsisting solely of spun glass braided on said wire, substantially asset forth.

2. An insulated electric conductor, consisting of a wire, a plurality ofcovering layers formed of strands of filaments consisting solely of spunglass braided on the same, and

intermediate braided layers of textile threads,

substantially as set forth.

In testimony that we claim the foregoing as our invention we have signedour names in presence of two subscribing witnesses.

HERMANN HAMMESFAIIR. ERNEST HAMMESFAHR. Witnesses:

PAUL GoErEL, HENRY SUIIRBIER.

